The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 27, 2004
Filed:
May. 08, 2001
Daicel Chemical Industries, Ltd., Osaka, JP;
Abstract
The present invention provides a cellulose triacetate which exhibits a satisfactory filtration performance Thus, the present invention provides a cellulose triacetate whose occlusion constant (K) determined by the following method is 70 or less. Method: the cellulose triacetate is dissolved in a solvent mixture of methylene chloride/methanol (9/1 w/w) to form a 16% by weight (as a solid concentration) solution, which is then filtered under a constant pressure at the filtration pressure of 3 kg/cm and the temperature of 25° C. using a muslin filter to determine a filtered volume with the lapse of time, from which the slope of a linear curve represented by t/V−t (wherein t is a filtration time (sec) and V is a filtered volume (ml)) is calculated to obtain an occlusion constant (K) where K=slope×2×10 .